This Metasploit module exploits a remote file include vulnerability in Railo, tested against version 4.2.1. First, a call using a vulnerable cffile line in thumbnail.cfm allows an attacker to download an arbitrary PNG file. By appending a .cfm, and taking advantage of a directory traversal, an attacker can append cold fusion markup to the PNG file, and have it interpreted by the server. This is used to stage and execute a fully-fledged payload.